ESA Satellite Recovers: Total Loss To Geostationary

Slimbob writes "About 2 years ago an Ariane 5 rocket malfunctioned and left a very expensive Artemis satellite in an unusable orbit. Well, over the course of 18 months, the European Space Agency actually managed to push the satellite into a usable orbit using measly 15mN ion thrusters! They managed the feat by reprogramming about 20% of the original control software and uplinking the patches to the satellite! See the ESA press release . Achievements include the first first major reprogramming of a telecommunications satellite, the first orbital transfer to geostationary orbit using ion propulsion, and the longest ever operational drift orbit."

Comments

Fuel

[GigsVT]

The article says they used up almost all the ion fuel, but yet it will still have enough for 10 years of trim thrusting, was the original planned life much longer, or did it just have that much extra fuel?

Re:Fuel

[Simon Field]

The article makes a distinction between the Xenon ion thrusters and "chemical propellant". The last orbital adjustments were made with "small chemical propellant thrusters, activated for the first time since launch".

It looks like the 10 years number does not refer to the Xenon ion thrusters.

Re:Fuel

[warpSpeed]

The article says they used up almost all the ion fuel, but yet it will still have enough for 10 years of trim thrusting, was the original planned life much longer, or did it just have that much extra fuel?

Since the operational drift is so much longer then what was originaly antisipated, I would be that they are consuming much less propellent then originaly expected, so they are able to get "10 years" out of what is left.

GStar 3 or 4, put up by GTE in the late 80s, had a simmilar fate. It was lobbed into a bad orbit, written off (paid for), and then slowly (very slowly) moved into a "usable" orbit. The satellite had less propellent avaiable to it, so it was allowed to drift up and down, and side to side.

GTE sold cheap time on the satellite since you could only get 5 to 20 minutes at a time without re-aiming your uplink antenna. A friend of mine wrote the software (in basic) that people used to aim thier uplinks antennas. However, since the satellite was paid for already, any money coming in was gravy at that point.

This isn't the first innovative satellite recovery

[Sierran]

A few years ago, Hughes Communications engineers used a lunar orbital slingshot maneuver to recover AsiaSat 1, which had been stranded in an unusable orbit. The insurance consortium that had already paid out for the satellite accepted a salvage deal with Hughes, who had manufactured it in the first place (it was launched on a Proton out of Baikonur). While they were using the designed maneuvering engines, as opposed to the stationkeeping thrusters, they ended up sending the satellite completely out of cislunar space in order to make the save.

Reference: Flug-Revue

"15mN ion thrusters"

[rthille]

15mN ion thrusters
See honey, size doesn't matter!

Re:"15mN ion thrusters"

[MrPeach]

It's not the size of the thrusters, it's the length of it's operation!

Re:Don't understand their error rate calculations

[Merlin42]

I think that instead of 109 it should have read 10 to the 9 or 10^9 ... now it makes perfect sense.

Cool Hack

[JGski]

This kind of hacking has been going on for >30 years by NASA and the military to save satellites. Certainly saving expensive spacecraft is one of the clearly positive aspects of hacking and hacking talents.

Expect more ions in the future

[TheSHAD0W]

The results of this botched lofting actually bode well for future satellite installations. Admittedly, using ion thrusters for final delivery would take much longer than using standard rocket technology, but it would also be enormously less expensive. The weight savings would be large, at a stage where weight is the most expensive part of the flight.

Wow

[robbo]

Imagine trying to do that to a windows box. With each patch you'd have to engineer a probe to go up and hit 'Ok' when it reminds you to reboot. ;-)

Re:On patching satellites

[OneFix]

Just a wild guess, but it's probably similar to how the Tivo does its update procedure. There are 2 boot partitions on the system...when an upgrade comes through, the system tests the integrity of the upgrade, switches the boot partition and reboots...

I would figure they probably use a more elaborate system...but it's probably the same in practice...of course, they have simulators/emulators on the ground that can accurately recreate the satelite's internal components...so, there should be no bugs in the system when the patches are sent...

The only thing they'ld need to worry about is noise on the uplink (corrupted files) and possible hardware failure...corrupted files could be tested for prior to patching, and hardware problems can be fixed by having backup systems...